Low temperature storage systems that store containers containing samples at low temperatures have hitherto been known. One such system includes a storage tray that accommodates a plurality of storage plates each holding a plurality of containers and stacked up and down, a low temperature storage chamber storing a plurality of storage trays, an operation room provided adjacent the low temperature storage chamber and kept at a lower temperature than that of the ambient environment, a loading/unloading chamber provided adjacent the operation room, a plate transfer mechanism provided inside the operation room for transferring the storage plates and loading and unloading them to and from the storage tray, and a pickup mechanism provided in the operation room and capable of picking containers individually from a storage plate (see, for example, Patent Literature 1).
The plate transfer mechanism includes a storage tray mover that conveys the storage trays individually from the low temperature storage chamber to the operation room in the up-down direction, and a storage plate mover that moves the storage plates individually out of and onto a storage tray. The plate transfer mechanism is configured to be movable inside the operation room.
In this low temperature storage system of Patent Literature 1, a plurality of containers are held on a storage plate, and a plurality of storage plates are held on a storage tray. When a desired container is to be retrieved from the low temperature storage chamber, the storage tray is removed from the low temperature storage chamber. After that, the storage plate is taken out of the storage tray in the operation room, and the desired container is picked up from the storage plate.